Heat-dissipating fan

ABSTRACT

A heat-dissipating fan for electronic equipment has a frame, a stator, an impeller, a top cover and an enlarged discharge port. The frame has a bottom, a sidewall and a volute. The sidewall is formed on the bottom and has an open front and a top surface that is either parallel to or diverges from the bottom of the frame toward the open front. The volute is defined inside the sidewall. The stator is mounted on the bottom in the frame. The impeller is mounted rotatably on the stator inside the frame. The top cover is mounted on the sidewall and has an inlet and an optional recessed segment. The enlarged discharge port reduces the back pressure on air passing through the volute.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fan, and more particularly to aheat-dissipating fan mounted inside electronic equipment to keepelectronic components such as a central process unit (CPU) or a harddrive (HDD) from overheating.

2. Description of Related Art

In general, electronic components such as chips or power supplies insideelectronic equipment generate heat that damages the electroniccomponents and even causes them to fail. Therefore, single or multiplefans are mounted inside the equipment to keep the components fromoverheating.

With reference to FIGS. 6 and 7, a conventional fan (90) for electronicequipment in accordance with prior art has a frame (91), a top cover(92), a stator and an impeller (96).

The frame (91) has a bottom, a sidewall and a volute (94). The bottomhas an inside surface and an outer edge. The sidewall is formed on theinside surface of the bottom flush with the outer edge and has a topsurface, a front, a right side, a left side and a discharge port (95).The discharge port (95) is formed in the front of the sidewall. Thevolute (94) is formed inside the sidewall and communicates with thedischarge port (95) in the sidewall.

The top cover (92) is mounted on the top surface of the sidewall of theframe (91) to enclose the volute (94) and has a bottom surface and aninlet (93). The bottom surface of the top cover (92) and the insidesurface of the bottom of the frame (91) are separated by a distance (a).The inlet (93) is formed through the top cover (92) and communicateswith the volute (94).

The stator is mounted securely on the bottom of the frame (91) in thevolute (94), is aligned with the inlet (93) and has motor coils (notshown). The motor coils are selectively connected to a source ofelectricity (not shown).

The impeller (96) is mounted rotatably and concentrically on the statorand has permanent magnets (not shown) and multiple blades. The permanentmagnets interact with the motor coils in the stator when the motor coilsare connected to a source of electricity and rotate the impeller (96) onthe stator. When the impeller (96) rotates, the blades draw ambient airthrough the inlet (93) into the volute (94) and push the air in thevolute (94) out through the discharge port (95).

To reduce the back pressure on the air in the volute (94), thetransverse cross sectional area of the volute (94) broadens graduallyfrom the right side of the sidewall to the discharge port (95).

However, the distance (a) is constant throughout the volute (94) and isan absolute limit to the broadening of the volute (94) as it approachesthe discharge port (95).

To overcome the shortcomings, the present invention provides aheat-dissipating fan to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The main objective of the invention is to provide a heat-dissipating fanfor electronic equipment, which dissipates heat efficiently.

A heat-dissipating fan for electronic equipment in accordance with thepresent invention comprises a frame, a stator, an impeller, a top coverand an enlarged discharge port. The frame has a bottom, a sidewall and avolute. The sidewall is formed on the bottom and has an open front and atop surface that is either parallel to or diverges from the bottom ofthe frame toward the open front. The volute is defined inside thesidewall. The stator is mounted on the bottom in the volute. Theimpeller is mounted rotatably on the stator inside the frame. The topcover is mounted on the sidewall and has an inlet and at least onerecessed segment. The inlet is aligned with the impeller. When the topof the sidewall is parallel to the bottom of the frame, the recessedsegment is formed adjacent to and forms part of the enlarged dischargeport and increases the cross sectional area of the volute near thedischarge port. The enlarged discharge port and cross sectional area ofthe volute reduce the back pressure on air passing through the volute.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a first embodiment of aheat-dissipating fan for electronic equipment in accordance with thepresent invention;

FIG. 2 is a top view of the fan in FIG. 1;

FIG. 3 is a side view in partial section of the fan in FIG. 1;

FIG. 4 is a side view in partial section of a second embodiment of aheat-dissipating fan for electronic equipment in accordance the presentinvention;

FIG. 5 is a top view of a third embodiment of a heat-dissipating fan forelectronic equipment in accordance the present invention;

FIG. 6 is a top view of a top view of a conventional heat-dissipatingfan for electronic equipment in accordance with the prior art.

FIG. 7 is a side view in partial section of the fan in FIG. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

With reference to FIGS. 1, 4 and 5, a heat-dissipating fan in accordancewith the present invention comprises a frame (10, 10 a), a stator (14),an impeller (20), a top cover (30, 30 a, 30 b) and an enlarged dischargeport (50, 50 a, 50 b).

The frame (10, 10 a) has a bottom (11), a sidewall (12, 12 a, 12 b) anda volute (13). The bottom (11) has an inside surface and an outer edge.The sidewall (12, 12 a, 12 b) is formed flush with the outer edge on andextends up from the inside surface of the bottom (11) and has a topsurface, a left side, a right side, a back and an open front. The topsurface is either parallel with the bottom (11) or diverges from thebottom (11) toward the open front and has multiple mounting protrusions(121). With further reference to FIG. 5, the right side of the frame (10b) is optionally open. The volute (13) is formed inside the sidewall(12, 12 a, 12 b), communicates with the open front of the sidewall (12,12 a) and the open right side of the sidewall (12 b) and has a heightdefined between the bottom surface of the top cover and the insidesurface of the bottom (11) of the frame (10).

The stator (14) is mounted securely on the inside surface of the bottom(11) of the frame (10) inside the volute (13) and close to the rightside of the sidewall (12, 12 a, 12 b).

The impeller (20) is mounted rotatably on the stator (14) inside thevolute (13) and has multiple blades.

The top cover (30, 30 a, 30 b) is mounted on the top surface of thesidewall (12) to enclose the volute (13) and has a front edge, a bottomsurface, an inlet (31), at least one recessed segment (32) and mountingholes (33). The inlet (31) is defined through the top cover (30) andcommunicates with the volute (13).

The enlarged discharge port (50, 50 a) is formed from the open front ofthe sidewall and the top cover, communicates with the volute (13) andhas a height. The height of the discharged port (50, 50 a) is definedbetween the front edge of the top cover (30, 30 a, 30 b) and the insidesurface of the bottom (11) of the frame (10, 10 a) and is larger thanthe height of the volute (13).

With further reference to FIGS. 2 and 3, the recessed segments (32) areformed in the bottom surface of the top cover (30, 30 a, 30 b) adjacentto the inlet (31) and the discharge port (50, 50 a, 50 b). The recessedsegments (32) become progressively deeper as the recessed segments (32)approach the open front of the sidewall (12, 12 a, 12 b). When the rightside of the sidewall (12 b) is open, the recessed segment (32 b)corresponds to the open front and the open right side of the sidewall(12 b).

The mounting holes (33) are defined through the top cover (30, 30 a, 30b), correspond to and respectively hold the mounting protrusions (121)of the sidewall (12, 12 a, 12 b).

In first and third embodiments of the heat-dissipating fan in accordancewith the present invention, the discharge ports (50, 50 a) are formedfrom the open front of the sidewall (12) and one of the recessedsegments (32, 32 b) in the bottom surface of the top cover (30, 30 a)and communicate with the volute (13). In the third embodiment of theheat-dissipating fan in accordance with the present invention, anotherone of the discharge port (50 b) is formed from an opening in the rightside wall and a recessed segment (32 b) in the bottom of the top cover(30 b) and communicates with the volute (13). One discharge port (50) isformed in the front and another discharge port (50 b) may be formed inthe right side.

The enlarged discharge ports (50, 50 a, 50 b), the recessed segments(32, 32 b) in the top cover (10, 10 b) and the diverging top cover (30a) help the broadening the volute (13) and allow air to blow out of theframe (10, 10 a, 10 b) more efficiently. Therefore, the coolingeffective of the heat-dissipating fan is improved.

Even though numerous characteristics and advantages of the presentinvention have been set forth in the foregoing description, togetherwith details of the structure and function of the invention, thedisclosure is illustrative only. Changes may be made in detail,especially in matters of shape, size, and arrangement of parts withinthe principles of the invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

1. A heat-dissipating fan comprising: a frame having a bottom having aninside surface; and an outer edge; a sidewall formed flush with theouter edge on and extending up from the inside surface of the bottom andhaving a top surface, a left side, a right side, a back and an openfront; and a volute formed inside the sidewall and communicating withthe open front of the sidewall and having a height defined between thebottom surface of the top cover and the inside surface of the bottom ofthe frame; a stator mounted securely on the inside surface of the bottomof the frame inside the volute and close to the right side of thesidewall; an impeller mounted rotatably on the stator inside the voluteand having multiple blades; a top cover mounted on the top surface ofthe sidewall and having a front edge; a bottom surface; and an inletdefined through the top cover and communicating with the volute; and anenlarged discharge port formed from the open front of the sidewall andthe top cover, communicating with the volute and having a height definedbetween the front edge of the top cover and the inside surface of thebottom of the frame and larger than the height of the volute.
 2. Theheat-dissipating fan as claimed in claim 1, wherein the top surface ofthe sidewall diverges from the bottom of the frame toward the openfront.
 3. The heat-dissipating fan as claimed in claim 1, wherein thetop surface of the sidewall is parallel with the bottom of the frame;and the bottom surface of the top cover has a recessed segment formedadjacent to the inlet.
 4. The heat-dissipating fan as claimed in claim1, wherein the right side of the sidewall of the frame is open andcommunicates with the volute to form a discharge port.
 5. Theheat-dissipating fan as claimed in claim 1, wherein the sidewall furtherhas multiple mounting protrusions formed on the top surface of thesidewall; and the top cover further has multiple mounting holes definedthrough the top cover, corresponding to and respectively holding themounting protrusions of the sidewall.
 6. The heat-dissipating fan asclaimed in claim 2, wherein the right side of the sidewall of the frameopens and communicates with the volute to form a discharge port.
 7. Theheat-dissipating fan as claimed in claim 3, wherein the right side ofthe sidewall of the frame opens and communicates with the volute to forma discharge port.
 8. The heat-dissipating fan as claimed in claim 3,wherein the number of the recessed segment is two and the recessedsegments becoming progressively deeper as the segments approach the openfront.